46 research outputs found

    Novel Allelic Variants in the Canine Cyclooxgenase-2 (Cox-2) Promoter Are Associated with Renal Dysplasia in Dogs

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    Renal dysplasia (RD) in dogs is a complex disease with a highly variable phenotype and mode of inheritance that does not follow a simple Mendelian pattern. Cox-2 (Cyclooxgenase-2) deficient mice have renal abnormalities and a pathology that has striking similarities to RD in dogs suggesting to us that mutations in the Cox-2 gene could be the cause of RD in dogs. Our data supports this hypothesis. Sequencing of the canine Cox-2 gene was done from clinically affected and normal dogs. Although no changes were detected in the Cox-2 coding region, small insertions and deletions of GC boxes just upstream of the ATG translation start site were found. These sequences are putative SP1 transcription factor binding sites that may represent important cis-acting DNA regulatory elements that govern the expression of Cox-2. A pedigree study of a family of Lhasa apsos revealed an important statistical correlation of these mutant alleles with the disease. We examined an additional 22 clinical cases from various breeds. Regardless of the breed or severity of disease, all of these had one or two copies of the Cox-2 allelic variants. We suggest that the unusual inheritance pattern of RD is due to these alleles, either by changing the pattern of expression of Cox-2 or making Cox-2 levels susceptible to influences of other genes or environmental factors that play an unknown but important role in the development of RD in dogs

    PAX4 Enhances Beta-Cell Differentiation of Human Embryonic Stem Cells

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    Background Human embryonic stem cells (HESC) readily differentiate into an apparently haphazard array of cell types, corresponding to all three germ layers, when their culture conditions are altered, for example by growth in suspension as aggregates known as embryoid bodies (EBs). However, this diversity of differentiation means that the efficiency of producing any one particular cell type is inevitably low. Although pancreatic differentiation has been reported from HESC, practicable applications for the use of β-cells derived from HESC to treat diabetes will only be possible once techniques are developed to promote efficient differentiation along the pancreatic lineages. Methods and Findings Here, we have tested whether the transcription factor, Pax4 can be used to drive the differentiation of HESC to a β-cell fate in vitro. We constitutively over-expressed Pax4 in HESCs by stable transfection, and used Q-PCR analysis, immunocytochemistry, ELISA, Ca2+ microfluorimetry and cell imaging to assess the role of Pax4 in the differentiation and intracellular Ca2+ homeostasis of β-cells developing in embryoid bodies produced from such HESC. Cells expressing key β-cell markers were isolated by fluorescence-activated cell sorting after staining for high zinc content using the vital dye, Newport Green. Conclusion Constitutive expression of Pax4 in HESC substantially enhances their propensity to form putative β-cells. Our findings provide a novel foundation to study the mechanism of pancreatic β-cells differentiation during early human development and to help evaluate strategies for the generation of purified β-cells for future clinical applications

    Fear of falling in obese women under 50 years of age: a cross-sectional study with exploration of the relationship with physical activity

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    An understanding of capacity for physical activity in obese populations should help guide interventions to promote physical activity. Fear of falling is a phenomenon reported in the elderly, which is associated with reduced mobility and lower physical activity levels. However, although falls are reportedly common in obese adults, fear of falling and its relationship with activity has not been investigated in younger obese populations. In a cross-sectional study, fear of falling was measured in 63 women aged 18 to 49 years, with mean BMI 42.1 kg/m (SD 10.3) using the Modified Falls Efficacy (MFES), the Consequences of Falling (COF) and the Modified Survey of Activities and Fear of Falling in the Elderly (MSAFFE) scales. The choice of scales was informed by prior qualitative interviews with obese younger women. Physical activity levels were measured at the same time using the International Physical Activity Questionnaire. The mean score for fear of falling scales, with 95% confidence intervals, were estimated. Chi-square tests and t-tests were used to explore differences in age, body mass index and fear of falling scores between fallers and non-fallers. For each fear of falling scale, binomial logistic regression was used to explore its relationship with physical activity. Mean scores suggested high levels of fear of falling: MFES [mean 7.7 (SD 2.7); median 8.5]; COF [mean 31.3 (SD 9.4)]; MSAFFE [mean 25.9 (SD 8.7); median 23]. Scores were significantly worse in fallers (  = 42) compared to non-fallers (  = 21). MFES and MSAFFE were independently associated with lower levels of physical activity [odds ratio = 0.65, 95% Cl 0.44 to 0.96 and odds ratio = 1.14, 95% CI 1.01 to 1.28 respectively], when adjusted for age, BMI and depression. This study confirms that fear of falling is present in obese women under 50 years of age. It suggests that it is associated with low levels of physical activity. These novel findings warrant further research to understand capacity for physical and incidental activity in obese adults in both genders and suggest innovative interventions to promote lifestyle changes and/or consideration of falls prevention in this population

    Epigenetic inactivation of the splicing RNA-binding protein CELF2 in human breast cancer.

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    To access publisher's full text version of this article, please click on the hyperlink in Additional Links field or click on the hyperlink at the top of the page marked DownloadHuman tumors show altered patterns of protein isoforms that can be related to the dysregulation of messenger RNA alternative splicing also observed in transformed cells. Although somatic mutations in core spliceosome components and their associated factors have been described in some cases, almost nothing is known about the contribution of distorted epigenetic patterns to aberrant splicing. Herein, we show that the splicing RNA-binding protein CELF2 is targeted by promoter hypermethylation-associated transcriptional silencing in human cancer. Focusing on the context of breast cancer, we also demonstrate that CELF2 restoration has growth-inhibitory effects and that its epigenetic loss induces an aberrant downstream pattern of alternative splicing, affecting key genes in breast cancer biology such as the autophagy factor ULK1 and the apoptotic protein CARD10. Furthermore, the presence of CELF2 hypermethylation in the clinical setting is associated with shorter overall survival of the breast cancer patients carrying this epigenetic lesion.Health Department PERIS-project of the Catalan Government (Generalitat de Catalunya) AGAUR of the Catalan Government (Generalitat de Catalunya) Instituto de Salud Carlos III Ministerio de Economia y Competitividad (MINECO) European Union (EU) Foundation CELLEX La Caixa Foundatio

    Diabetes mortality and trends before 25 years of age: an analysis of the Global Burden of Disease Study 2019

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    Background Diabetes, particularly type 1 diabetes, at younger ages can be a largely preventable cause of death with the correct health care and services. We aimed to evaluate diabetes mortality and trends at ages younger than 25 years globally using data from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019. Methods We used estimates of GBD 2019 to calculate international diabetes mortality at ages younger than 25 years in 1990 and 2019. Data sources for causes of death were obtained from vital registration systems, verbal autopsies, and other surveillance systems for 1990–2019. We estimated death rates for each location using the GBD Cause of Death Ensemble model. We analysed the association of age-standardised death rates per 100 000 population with the Socio-demographic Index (SDI) and a measure of universal health coverage (UHC) and described the variability within SDI quintiles. We present estimates with their 95% uncertainty intervals. Findings In 2019, 16 300 (95% uncertainty interval 14 200 to 18 900) global deaths due to diabetes (type 1 and 2 combined) occurred in people younger than 25 years and 73·7% (68·3 to 77·4) were classified as due to type 1 diabetes. The age-standardised death rate was 0·50 (0·44 to 0·58) per 100 000 population, and 15 900 (97·5%) of these deaths occurred in low to high-middle SDI countries. The rate was 0·13 (0·12 to 0·14) per 100 000 population in the high SDI quintile, 0·60 (0·51 to 0·70) per 100 000 population in the low-middle SDI quintile, and 0·71 (0·60 to 0·86) per 100 000 population in the low SDI quintile. Within SDI quintiles, we observed large variability in rates across countries, in part explained by the extent of UHC (r2=0·62). From 1990 to 2019, age-standardised death rates decreased globally by 17·0% (−28·4 to −2·9) for all diabetes, and by 21·0% (–33·0 to −5·9) when considering only type 1 diabetes. However, the low SDI quintile had the lowest decline for both all diabetes (−13·6% [–28·4 to 3·4]) and for type 1 diabetes (−13·6% [–29·3 to 8·9]). Interpretation Decreasing diabetes mortality at ages younger than 25 years remains an important challenge, especially in low and low-middle SDI countries. Inadequate diagnosis and treatment of diabetes is likely to be major contributor to these early deaths, highlighting the urgent need to provide better access to insulin and basic diabetes education and care. This mortality metric, derived from readily available and frequently updated GBD data, can help to monitor preventable diabetes-related deaths over time globally, aligned with the UN's Sustainable Development Targets, and serve as an indicator of the adequacy of basic diabetes care for type 1 and type 2 diabetes across nations.publishedVersio

    The global burden of cancer attributable to risk factors, 2010-19: a systematic analysis for the Global Burden of Disease Study 2019

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    Pan-cancer analysis of whole genomes

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    Cancer is driven by genetic change, and the advent of massively parallel sequencing has enabled systematic documentation of this variation at the whole-genome scale(1-3). Here we report the integrative analysis of 2,658 whole-cancer genomes and their matching normal tissues across 38 tumour types from the Pan-Cancer Analysis of Whole Genomes (PCAWG) Consortium of the International Cancer Genome Consortium (ICGC) and The Cancer Genome Atlas (TCGA). We describe the generation of the PCAWG resource, facilitated by international data sharing using compute clouds. On average, cancer genomes contained 4-5 driver mutations when combining coding and non-coding genomic elements; however, in around 5% of cases no drivers were identified, suggesting that cancer driver discovery is not yet complete. Chromothripsis, in which many clustered structural variants arise in a single catastrophic event, is frequently an early event in tumour evolution; in acral melanoma, for example, these events precede most somatic point mutations and affect several cancer-associated genes simultaneously. Cancers with abnormal telomere maintenance often originate from tissues with low replicative activity and show several mechanisms of preventing telomere attrition to critical levels. Common and rare germline variants affect patterns of somatic mutation, including point mutations, structural variants and somatic retrotransposition. A collection of papers from the PCAWG Consortium describes non-coding mutations that drive cancer beyond those in the TERT promoter(4); identifies new signatures of mutational processes that cause base substitutions, small insertions and deletions and structural variation(5,6); analyses timings and patterns of tumour evolution(7); describes the diverse transcriptional consequences of somatic mutation on splicing, expression levels, fusion genes and promoter activity(8,9); and evaluates a range of more-specialized features of cancer genomes(8,10-18).Peer reviewe

    A pathogenic role for germline PTEN variants which accumulate into the nucleus.

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    The PTEN gene encodes a master regulator protein that exerts essential functions both in the cytoplasm and in the nucleus. PTEN is mutated in the germline of both patients with heterogeneous tumor syndromic diseases, categorized as PTEN hamartoma tumor syndrome (PHTS), and a group affected with autism spectrum disorders (ASD). Previous studies have unveiled the functional heterogeneity of PTEN variants found in both patient cohorts, making functional studies necessary to provide mechanistic insights related to their pathogenicity. Here, we have functionally characterized a PTEN missense variant [c.49C>G; p.(Gln17Glu); Q17E] associated to both PHTS and ASD patients. The PTEN Q17E variant displayed partially reduced PIP3-catalytic activity and normal stability in cells, as shown using S. cerevisiae and mammalian cell experimental models. Remarkably, PTEN Q17E accumulated in the nucleus, in a process involving the PTEN N-terminal nuclear localization sequence. The analysis of additional germline-associated PTEN N-terminal variants illustrated the existence of a PTEN N-terminal region whose targeting in disease causes PTEN nuclear accumulation, in parallel with defects in PIP3-catalytic activity in cells. Our findings highlight the frequent occurrence of PTEN gene mutations targeting PTEN N-terminus whose pathogenicity may be related, at least in part, with the retention of PTEN in the nucleus. This could be important for the implementation of precision therapies for patients with alterations in the PTEN pathway
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